Bicycles also abhor a vacuum

Things have been going great with my 4th bike, though I still keep learning the hard way. I have been getting a lot more systematic in the way that I lay up the carbon, rather than just going on my gut instinct as to what will be strong enough and then overbuilding, I actually did some 3rd grade math and came up with a target for thickness and I went from there. I try to do my layup based on my semi-intuitive understanding of the forces for each joint and the notion that carbon is strongest in tension. I even had the forethought to cut all of the pieces of unidirectional carbon to size and shape before beginning the layup process, and going so far as to separate all of the pieces that would go on the tops and bottoms, lefts and rights of each joint. This has made the process MUCH faster. I've also been able to capitalize on the benefits of using the vacuum pump to a great degree, and occasionally to TOO great a degree.
I did the bottom bracket on Sunday night and laid up the whole joint at once, wrapped the release fabric and the breather ply, then sucked all the air out. Things seemed perfect. I unwrapped it the next morning and it looked great, stiff and solid. Then I tried fitting a wheel in. DOH. The force of the vacuum had distorted my rear triangle together, spacing the rear wheel at something like 120 mm. Bad news. I should have put a spacer in, but I thought that I had folded the bag in such a way that the dropout spacing would be unaffected. Wrong.

I'm weighing my options to proceed forward, and have had a modest bit of success in heating the BB joint and spreading the chainstays, but I'm not sure about the future strength once I do that. Epoxy is only flexible to a certain degree, and I hope I'm not creating too much internal stress. I'll give Gougeon Bros a call to double check and then hope for the best. Worst case scenario involves a gargantuan amount of sanding and then re-setting the joints. That should be only about 5 extra hours of work, maybe.

Pour moi?

I've finally started working on a bike for myself, after over a year of dinking with carbon and bamboo. This bike is going to have all the bells and whistles, or at least as many of the bells and whistles as I can manage to put together in one bike. I spent a long time anguishing over the frame geometry to specially suit my weirdo ideas about bike fit. I'm a true believer in the arch cleat position espoused by Steve Hogg and Joe Friel and I believe that it has had a lot to do with my continued improvement on the bicycle as well as a vast increase in comfort. I also made the switch to 180mm cranks last year and I've really enjoyed that change as well. A little sluggish at first, but more power, plus a really low center of gravity have made cornering a thing of joy. This means that I am very low and far forward on the bike though, which has resulted in a bit of sloppiness up in the front end with my extremely long and strange 140mm stem.

I've also decided to go with a tapered steer tube on the bike, though I am not 100% sure whether or not to go with a 1.5 or a 1.25 up front. I'm mostly concerned with what will look good with the enormous headtubes that I've ended up using. To top it all off, I'm a believer in the BB30 system as well, and though I won't be able to get my 180 cranks, i don't think, I'll be able to get a set of SRAM Red cranks in 177.5 which may be the sweet spot for me, we'll just have to see.

 

Sunset on the prairies. I was thinking of the Henningsgaard farm north of Bemidji where we passed several pre-preseasons and a most excellent Newyears, as well as Jude and Michelle's wedding.

Kids kick bikes

I'm kicking myself a bit now for not taking some better pictures of these things before I gave them away earlier, but here are some pics of my kids kick bikes that I made as christmas presents. They were literally finished 2 hours before Jennifer and I got on the plane to Minnesota. I put the last paint on them on Monday night, put them together on Tuesday before Christmas and we flew out that night. I just kinda winged the design and put them together based on what parts I could find for cheap. The shaft is bamboo, the legs are wood covered with fiberglass and carbon fiber. I was able to salvage some forks that had been damaged from the bike shop, and I got some seats for cheap. Unfortunately, they were out of white seats, so I got one that was incredibly pink. Yikes.

Since I was running out of time, I ended up not being able to get the surface of the carbon/fiberglass as smooth as I wanted, so I decided that a bit of bondo and some paint would be the best option. The single color black or white did only so much, and so I ended up getting creative with it, and spending an enormous amount of time with the new airbrush toy that I got from my friend Donnell. Airbrushes are cool, but they're also a great way to kill an entire weekend. On the bike for Shiloh I ended up painting a sunset theme, fading from blue to orange to yellow and red. I tried to make it reminiscent of a midwestern sunset over a farm, and even got inspired to paint a little farmhouse and tree on one of the rear stays. It looked pretty good. On the bike for Levi, I was inspired by the pattern of the carbon weave on the stays and went with a trout pattern. I got some awesome greens, white and some pink coloration and was able to do what I consider to be a decent looking rendition of a trout. Marye has promised to send me some action pictures when Levi gets old enough to really make use of the bike. Both of the kids are a bit too young for the bikes, but I wanted to make good use of our brief stop in Minneapolis this Christmas.